Reading through this thread again, I have to agree with whats been said. There is no need to put a large gas engine on a Kadet Sr. If you want to run an engine that size, get an appropriate airframe like the AMR 20 which is designed for a gas engine. A Kadet Sr. is designed for slow flying, is best kept as light as possible with power kept low also. I've flown a Senior ARF with an RCV-56, and it was more than ample power. It would take off and climb easily at 1/2 throttle.

I've got a Senior kit that will be built stock - 3-channel and powered by a Magnum .52 RFS. I'll do some training with it, but mainly just enjoy putting around with it as was intended to be done. And the exhaust residue will be at a minimum with this engine.

Hogflyer